Determining reference conditions of hemiboreal lakes in Latvia, NE Europe: a palaeolimnological approachNormunds Stivrins, Ieva Grudzinska, Kati Elmi, Atko Heinsalu and Siim VeskiAnn. Limnol. - Int. J. Lim., 54 (2018) 22DOI: https://doi.org/10.1051/limn/2018014